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JSON & XML Formatters

JSON Formatter

Format JSON online instantly with this free client-side JSON formatter and validator. Paste any JSON to get instant pretty-printing with 2, 4, or 8-space indentation, optional recursive key sorting, real-time syntax error diagnostics, and one-click copy or download. Essential for developers debugging API payloads, reviewing configuration files, and preparing JSON for readable diffs in version control.

JSON format and quality

In brief

Format JSON locally with indentation, optional key sorting, validation diagnostics, copy, and download actions.

What this tool supports

  • Strict JSON syntax parsing with local error reporting.
  • 2, 4, or 8-space pretty printing for readable API payloads.
  • Optional recursive object-key sorting for stable review diffs.
  • Copy and download actions for the formatted result.
  • Paste JSON and format it locally with 2, 4, or 8-space indentation, optional key sorting, syntax diagnostics, copy, and download output.
  • Paste raw JSON, minified JSON, arrays, or nested API responses.
  • Choose indentation and optionally sort object keys before formatting.
  • Copy or download the formatted result after syntax validation.
  • Client-side processing without application-server uploads
  • Keyboard-accessible controls and visible focus

How to Use JSON Formatter

Paste raw JSON from an API response, configuration file, or clipboard, choose your preferred indentation and optional key sorting, then format locally before copying or downloading the cleaned result. This tool runs entirely in your browser with no server uploads.

  • Step 1

    Paste or import raw JSON

    Paste a JSON object, array, string, number, boolean, or null into the input panel, or import a .json file from your device. You can also drag and drop a JSON file directly onto the input area. The formatter will immediately detect and highlight any syntax issues in the source.

  • Step 2

    Choose indentation and key sorting

    Select 2, 4, or 8 spaces for indentation width. Toggle the Sort Keys option to recursively sort all object keys alphabetically at every nesting level, producing stable and diff-friendly output that is easier to review in version control.

  • Step 3

    Format and review syntax diagnostics

    Click Format to process the input. The tool validates the JSON against RFC 8259 and displays either confirmed valid output or highlighted error positions with line and column references so you can locate and fix problems instantly.

  • Step 4

    Copy or download the formatted result

    Copy the formatted JSON to your clipboard for pasting into code editors or documentation, or download it as a .json file for use in version control, test fixtures, or API documentation.

Common mistakes

Pasting JavaScript object literals instead of JSON

Consequence: Unquoted keys, comments, undefined, or trailing commas will fail strict JSON parsing.

Fix: Convert the source to valid JSON before formatting.

Sorting keys before checking semantic order matters

Consequence: The content remains valid, but a human review may lose the original authoring order.

Fix: Use sorting for stable machine review, not when field order is part of your documentation.

Using malformed or incomplete input

Consequence: The parser cannot produce a trustworthy result.

Fix: Start with a known-good vector such as a JSON object, array, or API response body.

Treating transformed output as a security guarantee

Consequence: Readable or reversible data may be trusted incorrectly.

Fix: Formatting confirms JSON syntax only; it does not validate a business schema, sanitize private fields, or prove the data source is trusted.

Choosing the wrong format, algorithm, unit, or variant

Consequence: Another system may reject or misinterpret the result.

Fix: Confirm the receiver follows RFC 8259: JSON.

Skipping output verification

Consequence: Truncation, invalid syntax, or lossy changes can reach production.

Fix: Compare with validated JSON with chosen indentation and optional sorted object keys and round-trip when possible.

Sorting keys when field order carries semantic meaning

Consequence: The content remains valid but human review may lose the original authoring order that documents field relationships.

Fix: Use key sorting for stable machine review only. Keep original order when field sequence is part of your documentation or API contract.

Using formatted output as a security guarantee

Consequence: Readable or reversible data may be trusted incorrectly — formatting confirms syntax only.

Fix: Formatting validates JSON syntax, not business schema. Use JSON Schema validation for contract checks like required fields, type constraints, and format patterns.

Treating minified and formatted JSON as interchangeable

Consequence: Minified JSON may break tools expecting formatted input, and formatted JSON may exceed API size limits.

Fix: Use minified JSON for API payloads and network transfer. Use formatted JSON for debugging, code review, and documentation.

Ignoring encoding issues with Unicode characters

Consequence: Emoji, accented characters, and non-Latin scripts may produce unexpected escape sequences or display errors.

Fix: Verify that your JSON source uses UTF-8 encoding. The formatter preserves Unicode characters correctly in the output.

Best practices

  • Keep the raw source until the formatted result has been reviewed, so you can reprocess if needed.
  • Disable key sorting when field order carries semantic meaning or helps a human understand the payload structure.
  • Use a JSON Schema validator for contract validation beyond syntax checking, such as required fields, type constraints, and format patterns.
  • Download the output when you need a stable artifact for a ticket, test fixture, or documentation reference.
  • Keep a known test vector such as a JSON object, array, or API response body to verify formatting behavior.
  • Validate against RFC 8259 to confirm the output conforms to the JSON interchange format standard.
  • Compare formatted output at 100% zoom to catch visual truncation or encoding issues before committing to version control.
  • Use 2-space indentation for compact display and 4-space indentation for readability in code reviews.

Connected workflows

Prepare and process

JSON Formatter

Paste JSON and format it locally with 2, 4, or 8-space indentation, optional key sorting, syntax diagnostics, copy, and download output.

  1. Use supported input
  2. Choose relevant options
  3. Run locally
  4. Review diagnostics

Verify before integration

JSON FormatterJSON Minifier

Validate validated JSON with chosen indentation and optional sorted object keys before another application uses it.

  1. Run locally
  2. Verify the result
  3. Copy, download, or continue

Debug an API response

JSON FormatterJSON ValidatorJSON Tree Viewer

Paste a minified API response body, format it with key sorting, review the syntax diagnostics, and copy the readable result for debugging.

  1. Paste the minified API response
  2. Enable key sorting for stable review
  3. Click Format to validate and pretty-print
  4. Copy or download the formatted result

Prepare JSON for version control

JSON FormatterJSON MinifierJSON Sorter

Format JSON with consistent indentation before committing to ensure clean diffs and readable code reviews.

  1. Paste raw JSON from your codebase
  2. Choose 2-space or 4-space indentation
  3. Format and review for syntax errors
  4. Download the formatted file for commit

Convert between formats

JSON FormatterJSON to CSVJSON to YAML

Format JSON first, then export to CSV, YAML, or XML for use in other tools and systems.

  1. Format the raw JSON input
  2. Review the formatted output
  3. Export to CSV, YAML, or XML
  4. Download the converted result

Browser limitations

  • Multi-megabyte or deeply nested JSON can slow parsing, sorting, and rendering in the current tab.
  • The clipboard and downloads require browser permission and may be blocked in restricted contexts.
  • Deeply nested or multi-megabyte JSON can make parsing, sorting, and copying slower in a browser tab.

Authoritative resources

RFC 8259: JSONPublisher: rfc-editor.org · Reviewed: 2026-07-07MDN: JSON.parse()Publisher: developer.mozilla.org · Reviewed: 2026-07-07ECMA-404 JSON syntaxPublisher: ecma-international.org · Reviewed: 2026-07-07MDN: JSONPublisher: developer.mozilla.org · Reviewed: 2026-07-07

Concrete examples

Input
{"user":{"id":7,"roles":["admin","editor"]}}
Result
Readable indented JSON with the same values

This verifies syntax and makes nested API data easier to inspect without uploading it.

Frequently asked questions

How does JSON formatting differ from JSON validation?

JSON formatting restructures your JSON with proper indentation and optional key sorting for readability. JSON validation checks syntax correctness against RFC 8259 — verifying quoting, comma placement, bracket matching, and type correctness. This tool does both: it validates syntax first, then formats the valid result.

What is JSON and why should I format it?

JSON (JavaScript Object Notation) is a lightweight data-interchange format used by APIs, configuration files, and databases. Formatting JSON makes it human-readable by adding proper indentation, line breaks, and spacing — essential for debugging API payloads, reviewing configuration files, and preparing data for version control diffs.

How do I fix invalid JSON in JSON Formatter?

Paste your malformed JSON into the input panel and click Format. JSON Formatter highlights the exact error position with an RFC 8259 diagnostic so you can correct it instantly. Common issues include unquoted keys, trailing commas, missing colons, and JavaScript-style comments that are not valid in JSON.

Can JSON Formatter sort nested object keys?

Yes. Enable the Sort Keys option and JSON Formatter recursively sorts all object keys alphabetically at every nesting level before producing the formatted output. This produces stable, diff-friendly results that are easier to review in version control.

Does JSON Formatter validate API responses?

JSON Formatter checks JSON syntax only — correct structure, quoting, comma placement, and types. Paste any API response body into the input to verify it is valid JSON before using it in code, documentation, or test fixtures.

Is JSON Formatter safe for sensitive data?

Yes. JSON Formatter processes everything locally in your browser using the browser's native JSON.parse API. No data is uploaded to any server, making it safe for API keys, credentials, proprietary payloads, and production configuration files.

What is the difference between JSON Formatter and JSON Schema validation?

JSON Formatter validates JSON syntax — correct structure, quoting, and types. JSON Schema validation checks business rules like required fields, type constraints, enum values, and format patterns — those are separate validation steps that this tool does not perform.

How do I format minified or compacted JSON?

Paste the minified JSON string directly into the input panel and click Format. The formatter will expand the compact structure into readable indented output with your chosen indentation size.

What happens if I paste JavaScript object literals instead of JSON?

JavaScript object literals use unquoted keys, comments, undefined values, and trailing commas — all of which are invalid in strict JSON. The formatter will report parse errors for these constructs. Convert your source to valid JSON before formatting.

Privacy and offline behavior

JSON Formatter processes input and produces output inside this browser. The tool does not upload tool data. Browser capabilities such as files, clipboard, camera, Canvas, Web Crypto, workers, or downloads are used only after the workflow or an explicit user action requires them.